Orchard heater



DCC- 5, 1939. R. A. CAMPBELL 2,182,143

ORCHARD HEATER Filed May 6, 193'? [12T/*anion RJ?. Campbell latenteclDec. 5, 1939 UNITED STATES `PATENT oFFlcE ORCHARD HEATER Robert A.Campbell, Los Angeles, Calif.

Application May 6, 1937, Serial No. 141,117

6 Claims.

My invention relates to an oil burning type of heater vhaving some ofthe conventional features in that the oil in an oil receptacle isignited and initially consumed by air admitted through a 5 damper andwhat might be termed a secondary combustion takes place in the stack.

There are now on the market a number of more or less crude types oforchard heaters having the above mentioned characteristics in which dueto l incomplete combustion a great deal of smoke is developed and alsomost of the heat is lost by direct upward flow of hot air and theproducts of combustion. Another disadvantage of some of the presenttypes of heaters is that these clog fwNi with soot and heavy carbon,thereby reducing the proper draft and causing smoky combustion or elsesometimes entirely extinguishing the heater. Most of these types ofheaters have a more or less contracted throat on a cover of the oil pot,

)20 this leading to the stack. Such stack is provided 30 improvement bywhich there is a primary combustion of oil from the surface of the oilin the oil pot, this receiving the air for this primary combustionthrough a controllable damper much in the manner of the ordinary type oforchard Y 35 heater. 'Ihis air however is not suiicient to supportcomplete combustion. In my construction the throat of the oil pot iscontracted to form an I'annular passage by providing a central upwardair flow pipe which draws air from below the oil 40 pot. At the bottomof the stack I provide upwardly directed air ports which develop a sec-I ondary combustion of the hot gases and heavy oily vapors which passupwardly through the throat. Even if the flame is extinguished in thethroat by lack` of sucient air for combustion, the upwardly flowing oilproducts are suiiicient with the heated air through the air ports todevelop this secondary combustion.

An additional characteristic feature of my in- 50 vention is in theemployment of a combination ame spreader and additional air admissionstructure. This is located centrally in the stack ;55 ceiving air whichpasses upwardly through the kair iiow pipe located in the oil pot. Thisspreader directs the air outwardly into the combustible matter vpassingupwardly in the annular space between the spreader and the stack whichis slightly tapered upwardly. This air develops a third type ofcombustion or combustion zone in the lower portion of the stacksurrounding the iame spreader, this flame having a direct contact withthe stack which may be heated to a suicient degree for intense radiationof heat. 1U Such radiation is substantially horizontally in a completecircle surrounding the stack and on account of the radiation of aconsiderable amount of heat, the products of combustion leaving thestack are comparatively cool compared with the ordinary orchard heaterand therefore do not `develop such a rapid uplow of hot gases andproducts of combustion.

Another improvement embodied in my invention which may be applicable tothe ordinary oil pot with the conventional stack consists in confiningthe major portion of the initial combustion in an annular spacesurrounding the air upflow pipe which is centrally positioned in the oilpot. This is accomplished by providing a skirt or cylinder dependingfrom the cover of the oil pot positioned outwardly from the throat andsuch skirt has a plurality of vertical slot-like louvers. These louverspermit the initial ignition applied through a conventional iilling portand as this is started, air enters through the louvers so that thehottest oil is conned by the skirt surrounding the air upflow pipe. Thisdevelops hotter gases and hotter vapors which pass upwardly through thethroat to the position of secondary combustion adjacent the bottom ofthe stack. In addition, on account of thek hot burning oil and itsproducts of combustion sur- 'rounding the central air i'low pipe, suchair is highly heated before being discharged by the'40 name spreader.However, even with the conventional oilpot, the depending cylindricalskirt improves the combustion. It will be understood that the air forthe central supply may be derived by supporting the oil pot above theground in any suitable manner and providing air inlets to the air upflowpipe.

My invention is illustrated in connection with the accompanying drawing,in which:

Fig. 1 is a vertical section, part of the ame spreader being shown in'elevation and may be considered as taken substantially on the line I-lof Fig. 2 or 3.

Fig. 2 is a horizontal section o n the line 2 2 55 like.

of Fig. l in the direction of the arrows through the oil pot and theparts assembled therewith.

Fig. 3 is a horizontal section on the line 3--3 of Fig. l through thestack and the flame spreader.

Fig. i is an enlarged plan taken in the direction of the arrow li of thelling port with its closure cap and air inlet damper.

In my invention my oil pot designated by the extends upwardly an airflow pipe I9, this preferably having a flange at the bottom 20 which maybe Welded or otherwise secured to the bottom I outside of the opening I8by welding or the This air flow pipe is of quite large diameter comparedwith the diameter of the oil pot and has an upward slight taperterminating in the upper edge 2|.

The cover designated by the assembly numeral 25 has an upwardly slopingcover wall 2S with an annular shoulder 2'! and an internal rim 28, theshoulder engaging the'upper edge I'I of the peripheral wall of the oilpot and the flange 23 extending downwardly inside of the wall I2. Thecover is thus readily removable. A cylindrical neck 2Q extends upwardlyfrom the apex of the sloping cover wall 26 and at the top of the neckthere is a horizontal diverging wide flange 3o with a series of airinlet openings SI, these preferably being circular perforations.

'A rim 32 extends upwardly from the outer periphery of the ange 3d.. Acylinder or annular skirt 35 has an inturned flange or the like 36 whichis secured by welding to the sloping cover wall 28 whereby the skirtispositioned between the vertical line of the neck 2% and the peripheralwall i2. This cylinder or skirt has a series of louvers 3l formed byVertical slits 38 and inwardly bent louver edges 39. These arepreferably all directed in the same way so that the 'fiow of airentering the skirt develops a somewhat circular motion inside of suchskirt.

A conventional circular filler and ignition assembly S54 is provided bya circular opening d6 in the sloping cover wall 26 and below this thereis a slightly converging tube 47 secured to the underside of the coverwall and this has a plurality of vertical slots Q8. A cap 49 may beformed of a disc having a hinge 53 connecting to the sloping cover wall28. The disc is provided with a series of air ports 5i and above thecover there is a circular damper plate 52 having preferably a centralpivot 53 connecting with the damper plate and also having complementaryports 54 to register with the ports 5I. The damper may be turned by theoutwardly extending handle 55 which is also operative to tilt the capupwardly for filling the oil pot with oil and for igniting such oil, thefilling being through the slotted tube di and the ignition is also atsuch tube. v

The ame spreader and stack assembly employs aftapered stack 5I which isimperforate 0 and has its lower edge fitting outside of the rim 32 ofthe cover 25 and a bead 6l resting on the horizontalrirnv 32. The stackis thus readily removable. The discharge opening 62 at the top of thestack is concentric with the center of the oil pot and the air flow pipeIt.' A flame spreader 65 consists of a cylinder 65 with a closure top6l. The cylinder has a plurality of air outlet openings 58 formed byslight short vertical slits 69 and inwardly bent or flared sectio-ns lllto develop a somewhat circular motion of the air in the stack afterleaving the flame spreader. Below the cylinder there is a taperedsection 'il and a lower annular ring '12. This ring fits in the upperpart of the air flow pipe 10 i9 and as the upper edge of the pipeengages the tapered o-r converging part TI, it holds the flame spreaderin position and such spreader may be readily removed after removing thestack. In

- the illustrations the body of oil is indicated by 15 the numeral itiand the oil level is shown by the line '16. This leaves an annularlspace 'E7 devfined by the outside wall i2 ci the oill pot, the

skirt or cylinder 35 and a portion of the sloping cover 26. defined bythe skirt or cylinder 35 and the air upficw pipe i@ and also by aportion of the sloping wall 26 between the skirt and the neck 29. Anannular throat i9 is formed by the space inside of the vneck 2Q andoutside of the air up fio-w 25 pipe Iii. A secondary combustion chamberSID is immediately above the throat and receives air for combustionadmitted through theair openings 3l in the horizontal flange 38 and isdefined by the outer' lower portion of the stack and ,3.0

the tapered sectionl lI of the flame spreader. What may be termed athird combustion chamber or space 8l is the annular space surroundingthe flame spreader and limited by the tapered stack. The air for thiscombustion enters the ;35

openings I6 in the base i3, flows upwardly through the air flow pipe I9into the flame spreader where such air is heated additionally and theair flows outwardly through the air opening 68 being directed somewhatin a cir- 40 cular flow around theffiame spreader.

1n the operation of my orchard heater the equipment is assembled asillustrated and described presuming the oil pot is empty, kthis isfilled by lifting the cap 49 and pouring the ordinary type of oil` usedin this type of heater into the pipe 4l whence it flows through thebottom and the vertical slots d8, filling the oil pot to the desiredlevel. Manifestly the oil should never be sufciently high to entirelyblock uo the louver openings 3l and there should be sufficient space forthe'initial combustion of fuel in the oil pot. This oil is ignitedeither by inserting an inflammable material in the tube l1 and igniting`thisv or by utilizing a readily byurnablew,5 voil such yas kerosene orgasoline or, as is the" common practice,w by jetting the flamev of ablow torch through the Opem'ngliS, the cap being raised for thispurpose. The cap is then closed `and the damperis adjusted to secure'the de- A sired initial air' iiow through the registering portsf' 5I and5d. This causes an initial combustion of oil from the surface of the oilin the oil pot lin the chamber or space 'i'i and i3. As theoil becomeshot from this burning,A apparently most 6 of the combustion takes placein the chamber" lil, air and flames from [the space 17 entering throughthe louvers 3i. This initial combustion heats they air in the air fiowpipe I, the products of combustion from the space i8 flow uro-,170

wardly through the contracted throat li). This throat may partially oralmost completely quench the flame which arises directly from the oilusothat the products of combustion carry gases and neavyoil vapors whichhave a high temperature.` x

There is a second annular space 'i8 20 As soon as thiscombustible'product enters the secondary' combustion chamber 8i), itreceives air through the air ports 3l in the horizontal an'ge 3G, thisbeing sufficient to ignite and burn a considerable amount of the lightergases and the more readily ignitible vapors which burn in a circularllame lconfined by the lower portion of the stack and spread outwardlyby the tapered portion 'Il of the flame spreader 65. This secondarycombustion heads the less readily consumable oil'vapors and gases to astill higher temperature to which air is fed through the air openings inthe flame spreader. When the heater is in operation for but a short timethe air flowing upwardly through the air flow pipe i9 and Idistributedby this flame spreader has developed a high temperature vso that itreadily causes practically complete combustion with the gases and oilvapors in this third combustion space or chamber 8l. As above mentioned,the air entering through the flame spreader is given a swirl around theinside of the stack which tends to retard the speed of upward flo-w ofthe products of combustion and causes the flame to have an intenseheating action on the stack. The stack thus becomes highly heated andmanifestly radiates heat, most of this being substantially horizontaland through a complete circle. This radiation has a distinct advantagein orchard heating for in such heating it is necessary to place theheaters outside of the sweep or range of the foliage of individualtrees, usually spaced between adjacent trees'or sometimes equi-distantfrom four trees. The heat is thus radiated to the foliage of the trees,the trunks, branches -and to the air more or less confined underneathl'the foliage.

lof combustion are cool compared with the products of combustion fromthe present typical yorchard heater. Thus there is not such a violentupflow of the hot products of combustion and there is not such a decidedupward draft of warmed air developed but the heated air is con- 'nedmore or less to the immediate surroundings of the orchard and the airabove the trees.

It will be apparent that should I wish to use the ordinary type of oilpot with my flame spreader, I may omit the cylindrical skirt 35 but I ndthat I obtain improved combustion and less deposit of soot and carbon byusing this skirt than having an oil pot without such skirt. It is to beunderstood that my invention comprehends also an improvement in theordinary oil pot burning from the surface and having no central air flowpipe or iiame spreader, by providing the cylindrical skirt 35 with itslouvers, thus dividing the space above the oil in the oil pot into twodistinct annular chambers. This in itself gives an improved combustionand makes a simple addition to the ordinary orchard heater and suchskirt may be readily attached to the covers of heaters now in use atvery little expense.

While I have designated the structure 65 as a name spreader, this inreality has the function of being a relatively large diameter pipe forthe flow and the distribution of air internally in the stack. The airthus keeps the structure cool preventing its burning out from theintense heat and the air jetting out on all sides from the cylindricalportion B6 forces the flame against the inside of the stack. Thereforethe major portion of the hot flame does not come directly in contactwith the cylindrical portion 66 of this so-called flame spreader. Also,on account of the structure forming the flame spreader 65 beingcentrally `positioned above the throat of the cover and of the fire pot,any flame coming through the throat or the combustion immediately abovethe throat has the flame spread outwardly in contact with the'lowerportion of the stack. The flames from the various places of combustionfollow up the side of the stack practically completely to the top. Dueto the shape of the air outlet openings 68 it will be'noted that airdevelops a circular motion on'the inside of the stack which carriespractically'to the top of the stack, thus although there are certaineddies of the products of combustion above the flat top 6l' of the flamespreader, the

major portion of the flame is in close contact with the stack. A furtherfeature in regard to the circular motion of the products of combustionand the flame is that in the oil pot the louvers inthe skirt develop acirculation of the air ina counter-clockwise pipe I9. tinued upwardlythrough the throat and the air being discharged from the flame spreaderalso maintains this counter-clockwise circulation around the flamespreader. This general direction of circulation continues more or lessto the top of the stack.

-Various changes may be made in the details of the construction withoutdeparting from the spirit cr scope of the invention as defined by theappended claims.

I claim:

1. A heater comprising in combination an oil pot having a bottom with anopening, imperforate sides and a top cover with a contracted neckextending upwardly therefrom, an air flow pipe connected to the bottomat the opening 'and extending upwardly through the contracted neck Thisswirl is conand dening therewith an annular throat, an imperforatestack, means to support said stack above the neck, a skirt secured tothe top cover and extending downwardly towards the bottom of the voilvpot positioned between the neck and the outsidewalls of the pot, saidskirt having vertical louvers with inwardly extending edges from oneside of each louver to direct the ow of air for the primary combustioninto a somewhat circular motion in the space between the skirt and theair iiow pipe.

2. A heater comprising in combination an oil pot having a bottom, sidesand a top cover terminating in a vertical contracted neck, a flangeextending outwardly from the neck and an imperforate stack extendingupwardly from the flange, a skirt secured to the cover and extendingdownwardly towards the bottom of the oil pot but spaced from suchbottom, the skirt also being spaced outwardly from the neck and thuslocated between the neck and the outside walls of the oil pot, the skirthaving vertical louvers with inwardly extending edges from one side ofeach louver to direct the now of air for primary combustion into asomewhat circular motion in the space inside of the skirt, there beingan air inlet opening in the cover located between the skirt and theoutside walls of the oil pot.

3. A heater comprising in combination an oil pot having a bottom with acircular opening, an air flow pipe extending upwardly from said opening,means to support the oil pot above the ground and providing entrance forair to the lower end of the air pipe, a cover having a slopingcover wallsupported on and extending upwardly from the oil pot and having acontracted neck and an outwardly extending ange, the air ilow pipeextending upwardlythrough the neck and defining therewith an annularthroat, a tapered stack supported on the said flange and extendingupwardly, a ame spreader having a cylindrical structure closed at thetop and open at thebottom and `supported on the upper end of the air owpipe, 'said flame spreader having openings in its cylindrical structurefor admission of air to the stack anda controllable vair 110W means inthe cover for admitting air in the space above the level of oil in thepot whereby primary combustion may take place in said latter space andadditional combustion in the stack surrounding the ame spreader by airadmitted through said spreader, a skirt secured to the sloping coverwall spaced outwardly from the neck and extending downwardly towards thebottom of the oil pot, said skirt having vertical louvers with inwardlyextending edges from one side of each louver to direct the flow oi airfor the primary combustion into a somewhat circular motion in the spacebetween the skirt and the air ow pipe.

4. In an orchard heater in which an oil pot has a cover with a primarycombustion air inlet and a cylindrical neck extending upwardly from thecover, a flange on the top of the neck and an imperforate stackextending upwardly vfrom the ange comprising in combination the bottomof the oil pot having a central opening, an air flow pipe connected tosaid bottom opening and extending upwardly through the neck and definingtherewith a contracted annular throat communicating with the oil pot, acombined flame spreader and air distributor connected to the top of theair now pipe and extending upwardly a portion of the length of thestack, there being an annular space between the llame spreader and theinside of the stack, said space decreasing in .area towards the top ofthe ilame spreader, said flame spreader having air discharge openings invitsside only to direct air for combustion into said space.

5. A heater comprising in combination an oil pot having a bottom with acentral opening and an air ilow pipe extending upwardly through the potfrom said opening, means to support the pot above the ground level forflow of air to the lower end of said pipe, a stack with means to supportthe stack above the oil pot, a combined flame, spreader and airdistributor connected to the upper end out the air kow pipe and havingside openings only for admitting air to an annular space between theflame spreader and the stack and means to admit air to the oil pot abovethe level of oil therein for supporting initial combustion of the oil,the air admitted through the flame spreader being adapted to supportadditional combustion in the stack, ther means supporting the stackincluding a contracted throat structure and an outwardly extendingflange, the said ange having openings for admitting air to the bottom ofthe stack to be used in the combustion of fuel passing upwardly throughthe throat.

6. An oil heater comprising an oil pot having a bottom with a centralopening, cylindrical outside walls and a cover with a cylindrical neckextending upwardly from the cover, an air oW pipe connected to thebottom at the said opening and extending upwardly through the said neckand defining with the neck a contracted annular throat communicatingwith the pot, a flange connected to the upper end of the neck extendingoutwardly, an imperforate stack extending,

upwardly from the outside of the ilange, a flame spreader having a sidewall closed at the top and having a bottom opening and connected at thesaid bottom opening to the top of the air flow pipe, the said flamespreader having in its side wall a series of air openings to dischargeair flowing upwardly through the air flow pipe to the stack, there beingan annular space between the stack and the flame spreader decreasing inarea from bottom to top of the flame spreader, a

cylindrical skirt secured to the cover and spaced outwardly from theneck andfbetween the neck and the cylindrical outside walls from the oilpot, the said skirt terminating above the bottom of the oil pot, theskirt having `a plurality of vertical louvers with edges bent in anoffset manner to ldevelop a rotational swirl of air and the primarycombustion between the skirt and the air ilow pipe and in the annularthroat there being a controlled air inlet opening in the cover locatedbetween the skirt and the outside walls of the oil' pot to support theprimary combustion of oil, the primary combustion of oil being operativeto heat the air passing upwardly through the air flow pipe,

' ROBERT A. CAMPBELL.

